1 files changed, 169 insertions, 0 deletions
diff --git a/private/ntos/ke/i386/apcuser.c b/private/ntos/ke/i386/apcuser.c
new file mode 100644
index 000000000..14d327ec0
--- /dev/null
+++ b/private/ntos/ke/i386/apcuser.c
@@ -0,0 +1,169 @@
+/*++
+
+Copyright (c) 1990  Microsoft Corporation
+
+Module Name:
+
+    apcuser.c
+
+Abstract:
+
+    This module implements the machine dependent code necessary to initialize
+    a user mode APC.
+
+Author:
+
+    David N. Cutler (davec) 23-Apr-1990
+
+Environment:
+
+    Kernel mode only, IRQL APC_LEVEL.
+
+Revision History:
+
+--*/
+
+#include "ki.h"
+
+VOID
+KiInitializeUserApc (
+    IN PKEXCEPTION_FRAME ExceptionFrame,
+    IN PKTRAP_FRAME TrapFrame,
+    IN PKNORMAL_ROUTINE NormalRoutine,
+    IN PVOID NormalContext,
+    IN PVOID SystemArgument1,
+    IN PVOID SystemArgument2
+    )
+
+/*++
+
+Routine Description:
+
+    This function is called to initialize the context for a user mode APC.
+
+Arguments:
+
+    ExceptionFrame - Supplies a pointer to an exception frame.
+
+    TrapFrame - Supplies a pointer to a trap frame.
+
+    NormalRoutine - Supplies a pointer to the user mode APC routine.
+
+    NormalContext - Supplies a pointer to the user context for the APC
+        routine.
+
+    SystemArgument1 - Supplies the first system supplied value.
+
+    SystemArgument2 - Supplies the second system supplied value.
+
+Return Value:
+
+    None.
+
+--*/
+
+{
+
+    EXCEPTION_RECORD ExceptionRecord;
+    CONTEXT ContextFrame;
+    LONG Length;
+    ULONG UserStack;
+
+
+    //
+    // APCs are not defined for V86 mode; however, it is possible a
+    // thread is trying to set it's context to V86 mode - this isn't
+    // going to work, but we don't want to crash the system so we
+    // check for the possibility before hand.
+    //
+
+    if (TrapFrame->EFlags & EFLAGS_V86_MASK) {
+        return ;
+    }
+
+    //
+    // Move machine state from trap and exception frames to the context frame.
+    //
+
+    ContextFrame.ContextFlags = CONTEXT_FULL | CONTEXT_DEBUG_REGISTERS;
+    KeContextFromKframes(TrapFrame, ExceptionFrame, &ContextFrame);
+
+    //
+    // Transfer the context information to the user stack, initialize the
+    // APC routine parameters, and modify the trap frame so execution will
+    // continue in user mode at the user mode APC dispatch routine.
+    //
+
+
+    try {
+        ASSERT((TrapFrame->SegCs & MODE_MASK) != KernelMode); // Assert usermode frame
+
+        //
+        // Compute length of context record and new aligned user stack pointer.
+        //
+
+        Length = ((sizeof(CONTEXT) + CONTEXT_ROUND) &
+                    ~CONTEXT_ROUND) + sizeof(KAPC_RECORD);
+        UserStack = (ContextFrame.Esp & ~CONTEXT_ROUND) - Length;
+
+        //
+        // Probe user stack area for writeability and then transfer the
+        // context record to the user stack.
+        //
+
+        ProbeForWrite((PCHAR)UserStack, Length, CONTEXT_ALIGN);
+        RtlMoveMemory((PULONG)(UserStack + (sizeof(KAPC_RECORD))),
+                     &ContextFrame, sizeof(CONTEXT));
+
+        //
+        // Force correct R3 selectors into TrapFrame.
+        //
+
+        TrapFrame->SegCs = SANITIZE_SEG(KGDT_R3_CODE, UserMode);
+        TrapFrame->HardwareSegSs = SANITIZE_SEG(KGDT_R3_DATA, UserMode);
+        TrapFrame->SegDs = SANITIZE_SEG(KGDT_R3_DATA, UserMode);
+        TrapFrame->SegEs = SANITIZE_SEG(KGDT_R3_DATA, UserMode);
+        TrapFrame->SegFs = SANITIZE_SEG(KGDT_R3_TEB, UserMode);
+        TrapFrame->SegGs = 0;
+        TrapFrame->EFlags = SANITIZE_FLAGS( ContextFrame.EFlags, UserMode );
+
+        //
+        // If thread is supposed to have IOPL, then force it on in eflags
+        //
+
+        if (KeGetCurrentThread()->Iopl) {
+            TrapFrame->EFlags |= (EFLAGS_IOPL_MASK & -1);  // IOPL = 3
+        }
+
+        //
+        // Set the address of the user APC routine, the APC parameters, the
+        // new frame pointer, and the new stack pointer in the current trap
+        // frame. Set the continuation address so control will be transfered
+        // to the user APC dispatcher.
+        //
+
+        TrapFrame->HardwareEsp = UserStack;
+        TrapFrame->Eip = (ULONG)KeUserApcDispatcher;
+        TrapFrame->ErrCode = 0;
+        *((PULONG)UserStack)++ = (ULONG)NormalRoutine;
+        *((PULONG)UserStack)++ = (ULONG)NormalContext;
+        *((PULONG)UserStack)++ = (ULONG)SystemArgument1;
+        *((PULONG)UserStack)++ = (ULONG)SystemArgument2;
+    } except (KiCopyInformation(&ExceptionRecord,
+                                (GetExceptionInformation())->ExceptionRecord)) {
+
+        //
+        // Set the address of the exception to the current program address
+        // and raise the exception by calling the exception dispatcher.
+        //
+
+        ExceptionRecord.ExceptionAddress = (PVOID)(TrapFrame->Eip);
+        KiDispatchException(&ExceptionRecord,
+                            ExceptionFrame,
+                            TrapFrame,
+                            UserMode,
+                            TRUE);
+    }
+    return;
+}
+